Why Phoenix’s Skyline Has Stayed Low — And How It Compares to Los Angeles
Discover why Phoenix’s skyline lacks supertall skyscrapers, from FAA flight path limits near Phoenix Sky Harbor International Airport to how it compares with Los Angeles’s skyline growth.
Phoenix is the fifth-largest city in the United States, yet its skyline doesn’t resemble other major metros like Los Angeles, Chicago, or Dallas. Despite rapid population and economic growth, downtown Phoenix has long lacked supertall skyscrapers — and until recently, didn’t even have a building tall enough to qualify as a true “skyscraper” under standard definitions.
The Basics: Phoenix’s Height Reality
The tallest structure in Phoenix for decades has been Chase Tower, rising to about 483 feet. Under the Council on Tall Buildings and Urban Habitat definition, a skyscraper reaches at least 492 feet — which means Phoenix has technically lacked one — despite its size and population.
Why doesn’t Phoenix have super tall skyscrapers? 🤔🌵 It’s not what you think… ✈️ From FAA flight paths over Phoenix Sky Harbor International Airport to the city’s sprawling growth, there’s a hidden reason the skyline stayed low for decades. But that might be changing… 👀🏙️ Phoenix Arizona CityFacts UrbanPlanning Skyline DidYouKnow Infrastructure RealEstate USCities #STMdailynews♬ original sound – STMDailyNews – STMDailyNews
A new project, the Astra Tower, is planned to rise around 540+ feet when it breaks ground, potentially giving Phoenix its first true skyscraper.
Airport Proximity: The FAA’s Height Grid
FAA Obstacle Evaluation & Downtown Limits
Phoenix’s skyline constraints are rooted in aviation safety.
📍 Phoenix Sky Harbor International Airport sits just a few miles from downtown.
The Federal Aviation Administration (FAA) regulates building heights near airports so they don’t obstruct flight paths, require planes to alter approaches, or interfere with climb-out safety.
In Phoenix, this results in a layered set of height limits that vary by location and elevation above sea level — often measured in feet above mean sea level (MSL) rather than simply building height from ground.
The city’s zoning code divides downtown into multiple contour zones with distinct maximum elevation values (e.g., 1,275 ft, 1,525 ft, 1,700 ft MSL), each tied to how close it sits under airport flight paths.
That means in some blocks you can’t build above a specific elevation even if ground levels are lower — a regulatory “roof” that varies across downtown.
City zoning also explicitly states that no building can exceed the FAA’s airport height limits, even if other bonuses or zoning allowances exist.
Phoenix vs. Los Angeles: A Quick Comparison
Los Angeles: Higher Limits, Different Constraints
Cities like Los Angeles also have nearby airports (e.g., Los Angeles International Airport), but their key business districts aren’t directly under major flight corridors.
LA’s downtown has:
Taller office and residential towers
A financial core with dense development
Fewer FAA-driven overlays because the flight paths stretch past the downtown edge
Los Angeles’s tallest buildings — including Wilshire Grand Center (~1,100 ft) and U.S. Bank Tower (~1,018 ft) — were built where FAA restrictions don’t force low ceilings. FAA evaluations were conducted but didn’t cut as deeply into downtown zoning compared to Phoenix.
Phoenix, by contrast, sits right under approach and departure corridors — leading to consistent FAA involvement in almost every proposed mid- or high-rise downtown.
Economic and Planning Philosophies
Beyond FAA rules:
Advertisement
Phoenix developed in the automobile era, with vast inexpensive land encouraging horizontal growth.
Los Angeles grew earlier with heavier investment in centralized neighborhoods and higher density.
Phoenix’s village plan long encouraged multiple smaller hubs instead of concentrating all growth in one downtown core.
These historical differences mean Phoenix didn’t have the same economic “pressure” to build up — even with zoning that allows significant height if FAA permits are met.
What This Means for Phoenix’s Future
Phoenix still has room to grow vertically — but:
FAA height contours will remain the ceiling unless flight paths change
Developers must secure determinations of no hazard from the FAA before going taller
New projects like Astra show demand for taller buildings is rising
As Phoenix’s urban core densifies and land becomes scarcer, its skyline may yet reach higher — but always within the invisible grid drawn by aviation safety.
Dive into “The Knowledge,” where curiosity meets clarity. This playlist, in collaboration with STMDailyNews.com, is designed for viewers who value historical accuracy and insightful learning. Our short videos, ranging from 30 seconds to a minute and a half, make complex subjects easy to grasp in no time. Covering everything from historical events to contemporary processes and entertainment, “The Knowledge” bridges the past with the present. In a world where information is abundant yet often misused, our series aims to guide you through the noise, preserving vital knowledge and truths that shape our lives today. Perfect for curious minds eager to discover the ‘why’ and ‘how’ of everything around us. Subscribe and join in as we explore the facts that matter. https://stmdailynews.com/the-knowledge/
Rod: A creative force, blending words, images, and flavors. Blogger, writer, filmmaker, and photographer. Cooking enthusiast with a sci-fi vision. Passionate about his upcoming series and dedicated to TNC Network. Partnered with Rebecca Washington for a shared journey of love and art.
Why do people get headaches? – Evie V., age 10, Corpus Christi, Texas
Whether sharp and stabbing or dull and throbbing, a headache can ruin your day. But your brain doesn’t actually feel pain. So what is going on when it feels like your head is in a vise or about to explode? I am a child neurologist – that is, a doctor who specializes in diseases of the brain in kids. Most of my patients are kids and adolescents who are struggling with headaches. Head pain is complicated, and there is still a lot to learn about what causes it and how it can be treated. But researchers know there are a few key players that take part in generating pain.
What are headaches?
Nerves communicate information like pain through electrical signals between the body and the brain. While the brain itself doesn’t have any nerve sensors to feel pain, blood vessels in the head and structures that protect and surround the brain do sense pain. When these tissues detect injury or damage, they release chemicals that trigger transmission of electrical signals through nerves to tell the brain the head is hurting. The brain will also use nerves to signal the body to respond to pain with symptoms like feeling tired, teary eyes, runny nose, upset stomach and discomfort in bright or loud environments. It’s not clear why humans evolved to feel these symptoms, but some scientists theorize that this can lead to healthier lifestyle choices to decrease the chance of future headache attacks.Weather changes are one of the most commonly reported migraine triggers. Danielle Wilhour, a neurologist and headache specialist at University of Colorado Anschutz Medical Campus, explains why shifts in weather can bring on migraines — and what you can do to ease the pain.
What causes headaches?
Often, headaches are a sign that the body is under some kind of stress. That stress triggers chemical and physical changes to the nerves and blood vessels around your brain, head and neck that can cause headaches. Many types of stresses can cause headaches, including an infection, allergies, hormone changes during puberty and menstrual cycles, not getting enough sleep, not drinking enough water, skipping meals or drinking too much caffeine or alcohol. Sometimes, headaches happen with emotional stress, like feeling anxious or depressed. Even pressure in your sinuses due to changes in the weather can cause your head to hurt. One in 11 kids have had a type of severe headache called a migraine. They feel like a pulsing and pounding pain in your head and come with other symptoms, including nausea or being sensitive to lights and sounds. During a migraine, it can be hard to do everyday activities because they can make the pain worse. It is also very common to feel unwell or irritable before the head pain starts and after the pain is gone.Migraines and chronic headaches can be debilitating.Viktoriya Skorikova/Moment via Getty Images Migraines occur when the nerves and other structures used in signaling and interpreting pain aren’t working properly, leading to pain and discomfort from stimulation that wouldn’t normally provoke this. There are many environmental and genetic factors that contribute to this dysfunction. Some people are born with a higher risk of developing migraines. Most people with migraines have someone in their family who also experiences them.
What can treat and prevent headaches?
Identifying what type of headache you’re experiencing is crucial to making sure it is treated properly. Because migraines can be severe, they’re the type of headache that most often leads to doctor’s visits for both kids and adults. There are several ways to reduce your chances of having headaches, such as drinking plenty of water and limiting caffeine. Eating, sleeping and exercising regularly are other ways you can help prevent headaches.Sleep deprivation can worsen headaches.DjelicS/iStock via Getty Images Plus While painkillers like ibuprofen are often enough to relieve a headache, prescription medications are sometimes necessary to make head pain more bearable. Some medications can also help control or prevent headache episodes. Physical therapy to exercise the body or behavioral therapy to work on the mind can also help you manage headache pain. There are even electronic devices to treat headaches by stimulating different parts of the nervous system. It is important to talk with a doctor about headaches, especially if it’s a new problem or you experience a change in how they usually feel. Sometimes, brain imaging or blood tests are needed to rule out another health issue. Recognizing a headache problem early will help your doctor get started on helping you figure out the best way to treat it.Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.Katherine Cobb-Pitstick, Assistant Professor of Child Neurology, University of Pittsburgh This article is republished from The Conversation under a Creative Commons license. Read the original article.
Meet Irene Curie, the Nobel-winning atomic physicist who changed the course of modern cancer treatment
Artemis Spyrou, Michigan State University and Andrea Richard, Ohio University The adage goes “like mother like daughter,” and in the case of Irene Joliot-Curie, truer words were never spoken. She was the daughter of two Nobel Prize laureates, Marie Curie and Pierre Curie, and was herself awarded the Nobel Prize in chemistry in 1935 together with her husband, Frederic Joliot. While her parents received the prize for the discovery of natural radioactivity, Irene’s prize was for the synthesis of artificial radioactivity. This discovery changed many fields of science and many aspects of our everyday lives. Artificial radioactivity is used today in medicine, agriculture, energy production, food sterilization, industrial quality control and more.Frederic Joliot and Irene Joliot-Curie.Wellcome Collection, CC BY We are two nuclear physicistswho perform experiments at different accelerator facilities around the world. Irene’s discovery laid the foundation for our experimental studies, which use artificial radioactivity to understand questions related to astrophysics, energy, medicine and more.
Early years and battlefield training
Irene Curie was born in Paris, France, in 1897. In an unusual schooling setup, Irene was one of a group of children taught by their academic parents, including her own by then famous mother, Marie Curie.Marie Curie and her daughter Irene were both scientists studying radioactivity.Wellcome Collection, CC BY World War I started in 1914, when Irene was only 17, and she interrupted her studies to help her mother find fragments of bombs in wounded soldiers using portable X-ray machines. She soon became an expert in these wartime radiology techniques, and on top of performing the measurements herself, she also spent time training nurses to use the X-ray machines. After the war, Irene went back to her studies in her mother’s lab at the Radium Institute. This is where she met fellow researcher Frederic Joliot, whom she later married. The two worked together on many projects, which led them to their major breakthrough in 1934.
A radioactive discovery
Isotopes are variations of a particular element that have the same number of protons – positively charged particles – and different numbers of neutrons, which are particles with no charge. While some isotopes are stable, the majority are radioactive and called radioisotopes. These radioisotopes spontaneously transform into different elements and release radiation – energetic particles or light – in a process called radioactive decay. At the time of Irene and Frederic’s discovery, the only known radioactive isotopes came from natural ores, through a costly and extremely time-consuming process. Marie and Pierre Curie had spent years studying the natural radioactivity in tons of uranium ores. In Irene and Frederic’s experiments, they bombarded aluminum samples with alpha particles, which consist of two protons and two neutrons bound together – they are atomic nuclei of the isotope helium-4. In previous studies, they had observed the different types of radiation their samples emitted while being bombarded. The radiation would cease when they took away the source of alpha particles. In the aluminum experiment, however, they noticed that even after they removed the alpha source, they could still detect radiation. The amount of radiation decreased by half every three minutes, and they concluded that the radiation came from the decay of a radioisotope of the element phosphorus. Phosphorus has two additional protons compared to aluminum and was formed when the alpha particles fused with the aluminum nuclei. This was the first identification of an artificially made radioisotope, phosphorus-30. Because phosphorus-30 was created after bombarding aluminum with alpha particles – rather than occurring in its natural state – Irene and Frederic induced the radioactivity. So, it is called artificial radioactivity.In Irene and Frederic’s experiments, an isotope of aluminum was hit with an alpha particle (two neutrons and two protons bound together). The collision resulted in two protons and a neutron from the alpha particle binding to the aluminum, making it an isotope of phosphorus, which decayed, releasing a particle called a positron.Artemis Spyrou After her major discovery, Irene stayed active not only in research but in activism and politics as well. In 1936, almost a decade before women gained the right to vote in France, she was appointed under secretary of state for scientific research. In this position, she laid the foundations for what would become the National Centre for Scientific Research, which is the French equivalent of the U.S. National Science Foundation or National Institutes of Health. She co-created the French Atomic Energy Commission in 1945 and held a six-year term, promoting nuclear research and development of the first French nuclear reactor. She later became director of the Curie Laboratory at the Radium Institute and a professor at the Faculty of Science in Paris.
Medical uses of artificial radioactivity
The Joliot-Curie discovery opened the road to the extensive use of radioisotopes in medical applications. Today, radioactive iodine is used regularly to treat thyroid diseases. Radioisotopes that emit positrons – the positive equivalent of the electron – are used in medical PET scans to image and diagnose cancer, and others are used for cancer therapy. To diagnose cancer, practitioners can inject a small amount of the radioisotope into the body, where it accumulates at specific organs. Specialized devices such as a PET scanner can then detect the radioactivity from the outside. This way, doctors can visualize how these organs are working without the need for surgery. To then treat cancer, practitioners use large amounts of radiation to kill the cancer cells. They try to localize the application of the radioisotope to just where the cancer is so that they’re only minimally affecting healthy tissue.
An enduring legacy
In the 90 years since the Joliot-Curie discovery of the first artificial radioisotope, the field of nuclear science has expanded its reach to roughly 3,000 artificial radioisotopes, from hydrogen to the heaviest known element, oganesson. However, nuclear theories predict that up to 7,000 artificial radioisotopes are possible. As physicists, we work with data from a new facility at Michigan State University, the Facility for Rare Isotope Beams, which is expected to discover up to 1,000 new radioisotopes.Scientists graph the known isotopes in the chart of nuclei. They have discovered roughly 3,000 radioisotopes (shown with cyan boxes) and predict the existence of another 4,000 radioisotopes (shown with gray boxes).Facility for Rare Isotope Beams While the Joliot-Curies were bombarding their samples with alpha particles at relatively low speeds, the Michigan State facility can accelerate stable isotopes up to half the speed of light and smash them on a target to produce new radioisotopes. Scientists using the facility have already discovered five new radioisotopes since it began operating in 2022, and the search continues. Each of the thousands of available radioisotopes has a different set of properties. They live for different amounts of time and emit different types of radiation and amounts of energy. This variability allows scientists to choose the right isotope for the right application. Iodine, for example, has more than 40 known radioisotopes. A main characteristic of radioisotopes is their half-life, meaning the amount of time it takes for half of the isotopes in the sample to transform into a new element. Iodine radioisotopes have half-lives that span from a tenth of a second to 16 million years. But not all of them are useful, practical or safe for thyroid treatment.The iodine radioisotope used in cancer therapy has a half-life of eight days. Eight days is long enough to kill cancer cells in the body, but not so long that the radioactivity poses a long-term threat to the patient and those around them.Artemis Spyrou Radioisotopes that live for a few seconds don’t exist long enough to perform medical procedures, and radioisotopes that live for years would harm the patient and their family. Because it lives for a few days, iodine-131 is the preferred medical radioisotope. Artificial radioactivity can also help scientists study the universe’s mysteries. For example, stars are fueled by nuclear reactions and radioactive decay in their cores. In violent stellar events, such as when a star explodes at the end of its life, they produce thousands of different radioisotopes that can drive the explosion. For this reason, scientists, including the two of us. produce and study in the lab the radioisotopes found in stars. With the advent of the Facility for Rare Isotope Beams and other accelerator facilities, the search for new radioisotopes will continue opening doors to a world of possibilities. Artemis Spyrou, Professor of Nuclear Physics, Michigan State University and Andrea Richard, Assistant Professor of Physics and Astronomy, Ohio University This article is republished from The Conversation under a Creative Commons license. Read the original article.
A Short-Form Series from The Knowledge by STM Daily News
Every Friday, STM Daily News shines a light on brilliant minds history overlooked.
Forgotten Genius Fridays is a weekly collection of short videos and articles dedicated to inventors, innovators, scientists, and creators whose impact changed the world—but whose names were often left out of the textbooks.
From life-saving inventions and cultural breakthroughs to game-changing ideas buried by bias, our series digs up the truth behind the minds that mattered.
Each episode of The Knowledge runs 30–90 seconds, designed for curious minds on the go—perfect for YouTube Shorts, TikTok, Reels, and quick reads.
Because remembering these stories isn’t just about the past—it’s about restoring credit where it’s long overdue.
Unlikely Collaborators is bringing astrophysicist Dr. Lisa Kaltenegger to Santa Monica for a conversation centered on one of science’s most enduring questions: Are we alone in the universe? The event, part of the organization’s Spark Salon series, took place on March 17 at 7:00 p.m. PT and was offered both in person and via livestream.
Kaltenegger, founding director of the Carl Sagan Institute at Cornell University and a professor of astronomy, is widely recognized for her work on habitable exoplanets and the search for detectable signs of life beyond Earth. Her talk focused not only on the science of planet hunting, but also on the assumptions people bring to questions about life, habitability, and reality itself.
On March 17 at 7 PM PT, Unlikely Collaborators hosts Cornell astronomer and Carl Sagan Institute Founding Director Dr. Lisa Kaltenegger for Spark Salon: Are We Alone in the Universe? Explore the search for life on distant worlds and the deeper question of how our assumptions shape what we recognize as life, reality, and possibility. In person in Santa Monica + livestream.
According to the event announcement, the discussion examined how scientists interpret data from distant worlds and asked broader questions about what counts as life, what makes a planet habitable, and how human perspective can shape discovery. The program also highlighted how the search for life beyond Earth can challenge long-held ideas about what is normal, possible, and even alive.
The evening included a reception, the main program, and a book signing. In-person guests also received a complimentary copy of Kaltenegger’s book, Alien Earths: The New Science for Planet Hunting in the Cosmos.
Unlikely Collaborators, founded by Elizabeth R. Koch, describes itself as a nonprofit focused on helping people better understand themselves and the world through its Perception Box framework. The Spark Salon series regularly brings together researchers, artists, and thought leaders for conversations designed to challenge perspective and encourage reflection.
Dive into “The Knowledge,” where curiosity meets clarity. This playlist, in collaboration with STMDailyNews.com, is designed for viewers who value historical accuracy and insightful learning. Our short videos, ranging from 30 seconds to a minute and a half, make complex subjects easy to grasp in no time. Covering everything from historical events to contemporary processes and entertainment, “The Knowledge” bridges the past with the present. In a world where information is abundant yet often misused, our series aims to guide you through the noise, preserving vital knowledge and truths that shape our lives today. Perfect for curious minds eager to discover the ‘why’ and ‘how’ of everything around us. Subscribe and join in as we explore the facts that matter. https://stmdailynews.com/the-knowledge/